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Aussie miner Thor (up 9 per cent today at 0.52p) was also on the rise as a ‘private sophisticated investor’ provided the firm with A$1million to finance the development of its projects in the Northern Territory.

Meanwhile, AIM-quoted Greencore (down 13 per cent today at 88.5p) was among the fallers as it became the latest food supplier to be pulled into the horsemeat scandal, after beef bolognese sauce was withdrawn from ASDA stores after traces of horse DNA were detected.

After months of anticipation Beacon Hill's (down one per cent today at 4.9p) investors finally welcomed the news that it had successfully secured a slot on the Sena railway line to transport higher volumes of coking coal to the Port of Beira for export.

It confirmed on Monday that it will be able to move 0.5million tonnes of coking coal per year on the railway, starting at the end of the current quarter.

Fellow East Africa mining group Richland Resources (unchanged today at 6.62p) was also among the week's risers, shooting up 40 per cent after its insurers approved a $1.4million payout on Wednesday following a break-in at the group's tanzanite mining operation in Tanzania.

Previously, on Monday, it reported a strong set of results - with improved production output and grade. However, the impact of the thefts overshadowed the upbeat statement somewhat.

South African mining contractor Shaft Sinkers (unchanged today at 47.5p) also revealed a set of results that was laced with positivity. It predicted much better profits in 2013, while orders had also improved.

Last year was tough. Revenue for the whole of 2012 is expected to be 13 per cent lower than in 2011 at around £197million, although in constant currency terms that was a three per cent shortfall.

The good news is that profitability for the current year is expected to be significantly higher than in 2012, benefiting from a full year contribution from the two new contracts awarded in 2012, an improved operational performance and the contribution from expected new contract awards in 2013.

Tertiary Minerals (down three per cent today at 8.25p), another of AIM's mining stocks, also reached a keenly awaited milestone this week as it unveiled a report from its consultants assessing its recently acquired MB fluorspar project in Nevada, USA.

The report confirmed MB's world class potential, estimating that it could host between 85 and 105million tonnes of mineralisation grading between 9 and 11 per cent fluorspar. The industrial metal primarily used in the manufacturing of specialist alloys.

The estimate suggests the potential for at least 8million tonnes of contained fluorspar, which makes MB twice as large as the firm's two Scandinavian mine development projects combined.

Investors, however, appear to have taken an opportunity to take profits on the stock which had almost tripled in value since the turn of the year. This week it pulled back after reaching nearly 14p on Tuesday.

Kea Petroleum (up 6.5 per cent today at 10.12p) shares gained over 30 per cent this week after it hit a new oil discovery in the Puka 2 well in the Taranaki basin in New Zealand.

The breakthrough will deliver production revenues in the near term and it has also expanded the potential size of the Puka field.

Irish oil firm Providence Resources (unchanged today at 589p) suffered a setback to a proposed drill programme off the Dublin coast as it decided to surrender a licence because of a problem with Irish legislation, which could have left the firm open to a legal challenge from environmental groups.

It is understood that the legislation is being tightened and subsequently Providence will re-apply.

The upshot is that the Dalkey Island exploration well, originally slated for the second half of this year, will not now be drilled until mid-2014 at the earliest.

Troubled tantalum producer Noventa (up 2.5 per cent today at 1p) was the week’s biggest loser after it shed over 60 per cent following a default on a rescue loan it secured last August.

It blamed lower than expected production from its Marropino mine in Mozambique and said that lower ore grades going forward now mean it will not be able to meet the terms of the loan.

‘If the default is confirmed and the lender exercises its remedies, the company will in all likelihood become immediately insolvent,’ Noventa warned in a statement.